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Diffstat (limited to 'gdb/lin-thread.c')
| -rw-r--r-- | gdb/lin-thread.c | 2140 |
1 files changed, 2140 insertions, 0 deletions
diff --git a/gdb/lin-thread.c b/gdb/lin-thread.c new file mode 100644 index 00000000000..2f255c0e54a --- /dev/null +++ b/gdb/lin-thread.c @@ -0,0 +1,2140 @@ +/* Multi-threaded debugging support for the thread_db interface, + used on operating systems such as Solaris and Linux. + Copyright 1999 Free Software Foundation, Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +/* This module implements a thread_stratum target that sits on top of + a normal process_stratum target (such as procfs or ptrace). The + process_stratum target must install this thread_stratum target when + it detects the presence of the thread_db shared library. + + This module will then use the thread_db API to add thread-awareness + to the functionality provided by the process_stratum target (or in + some cases, to add user-level thread awareness on top of the + kernel-level thread awareness that is already provided by the + process_stratum target). + + Solaris threads (for instance) are a multi-level thread implementation; + the kernel provides a Light Weight Process (LWP) which the procfs + process_stratum module is aware of. This module must then mediate + the relationship between kernel LWP threads and user (eg. posix) + threads. + + Linux threads are likely to be different -- but the thread_db + library API should make the difference largely transparent to GDB. + + */ + +/* The thread_db API provides a number of functions that give the caller + access to the inner workings of the child process's thread library. + We will be using the following (others may be added): + + td_thr_validate Confirm valid "live" thread + td_thr_get_info Get info about a thread + td_thr_getgregs Get thread's general registers + td_thr_getfpregs Get thread's floating point registers + td_thr_setgregs Set thread's general registers + td_thr_setfpregs Set thread's floating point registers + td_ta_map_id2thr Get thread handle from thread id + td_ta_map_lwp2thr Get thread handle from LWP id + td_ta_thr_iter Iterate over all threads (with callback) + + In return, the debugger has to provide certain services to the + thread_db library. Some of these aren't actually required to do + anything in practice. For instance, the thread_db expects to be + able to stop the child process and start it again: but in our + context, the child process will always be stopped already when we + invoke the thread_db library, so the functions that we provide for + the library to stop and start the child process are no-ops. + + Here is the list of functions which we export to the thread_db + library, divided into no-op functions vs. functions that actually + have to do something: + + No-op functions: + + ps_pstop Stop the child process + ps_pcontinue Continue the child process + ps_lstop Stop a specific LWP (kernel thread) + ps_lcontinue Continue an LWP + ps_lgetxregsize Get size of LWP's xregs (sparc) + ps_lgetxregs Get LWP's xregs (sparc) + ps_lsetxregs Set LWP's xregs (sparc) + + Functions that have to do useful work: + + ps_pglobal_lookup Get the address of a global symbol + ps_pdread Read memory, data segment + ps_ptread Read memory, text segment + ps_pdwrite Write memory, data segment + ps_ptwrite Write memory, text segment + ps_lgetregs Get LWP's general registers + ps_lgetfpregs Get LWP's floating point registers + ps_lsetregs Set LWP's general registers + ps_lsetfpregs Set LWP's floating point registers + ps_lgetLDT Get LWP's Local Descriptor Table (x86) + + Thus, if we ask the thread_db library to give us the general registers + for user thread X, thread_db may figure out that user thread X is + actually mapped onto kernel thread Y. Thread_db does not know how + to obtain the registers for kernel thread Y, but GDB does, so thread_db + turns the request right back to us via the ps_lgetregs callback. */ + +#include "defs.h" +#include "gdbthread.h" +#include "target.h" +#include "inferior.h" +#include "gdbcmd.h" + +#ifdef HAVE_WAIT_H +#include <wait.h> +#else +#ifdef HAVE_SYS_WAIT_H +#include <sys/wait.h> +#endif +#endif + +/* "wait.h" fills in the gaps left by <wait.h> */ +#include "wait.h" + +#include <time.h> + +#if defined(USE_PROC_FS) || defined(HAVE_GREGSET_T) +#include <sys/procfs.h> +#endif + +#if defined (HAVE_PROC_SERVICE_H) +#include <proc_service.h> /* defines incoming API (ps_* callbacks) */ +#else +#include "gdb_proc_service.h" +#endif + +#if defined HAVE_STDINT_H /* Pre-5.2 systems don't have this header */ +#if defined (HAVE_THREAD_DB_H) +#include <thread_db.h> /* defines outgoing API (td_thr_* calls) */ +#else +#include "gdb_thread_db.h" +#endif + +#include <dlfcn.h> /* dynamic library interface */ + +#ifndef TIDGET +#define TIDGET(PID) (((PID) & 0x7fffffff) >> 16) +#define PIDGET(PID) (((PID) & 0xffff)) +#define MERGEPID(PID, TID) (((PID) & 0xffff) | ((TID) << 16)) +#endif + +/* Macros for superimposing PID and TID into inferior_pid. */ +#define THREAD_FLAG 0x80000000 +#define is_thread(ARG) (((ARG) & THREAD_FLAG) != 0) +#define is_lwp(ARG) (((ARG) & THREAD_FLAG) == 0) +#define GET_LWP(PID) TIDGET (PID) +#define GET_THREAD(PID) TIDGET (PID) +#define BUILD_LWP(TID, PID) MERGEPID (PID, TID) +#define BUILD_THREAD(TID, PID) (MERGEPID (PID, TID) | THREAD_FLAG) + +/* + * target_beneath is a pointer to the target_ops underlying this one. + */ + +static struct target_ops *target_beneath; + + +/* + * target vector defined in this module: + */ + +static struct target_ops thread_db_ops; + +/* + * Typedefs required to resolve differences between the thread_db + * and proc_service API defined on different versions of Solaris: + */ + +#if defined(PROC_SERVICE_IS_OLD) +typedef const struct ps_prochandle *gdb_ps_prochandle_t; +typedef char *gdb_ps_read_buf_t; +typedef char *gdb_ps_write_buf_t; +typedef int gdb_ps_size_t; +#else +typedef struct ps_prochandle *gdb_ps_prochandle_t; +typedef void *gdb_ps_read_buf_t; +typedef const void *gdb_ps_write_buf_t; +typedef size_t gdb_ps_size_t; +#endif + +/* + * proc_service callback functions, called by thread_db. + */ + +ps_err_e +ps_pstop (gdb_ps_prochandle_t ph) /* Process stop */ +{ + return PS_OK; +} + +ps_err_e +ps_pcontinue (gdb_ps_prochandle_t ph) /* Process continue */ +{ + return PS_OK; +} + +ps_err_e +ps_lstop (gdb_ps_prochandle_t ph, /* LWP stop */ + lwpid_t lwpid) +{ + return PS_OK; +} + +ps_err_e +ps_lcontinue (gdb_ps_prochandle_t ph, /* LWP continue */ + lwpid_t lwpid) +{ + return PS_OK; +} + +ps_err_e +ps_lgetxregsize (gdb_ps_prochandle_t ph, /* Get XREG size */ + lwpid_t lwpid, + int *xregsize) +{ + return PS_OK; +} + +ps_err_e +ps_lgetxregs (gdb_ps_prochandle_t ph, /* Get XREGS */ + lwpid_t lwpid, + caddr_t xregset) +{ + return PS_OK; +} + +ps_err_e +ps_lsetxregs (gdb_ps_prochandle_t ph, /* Set XREGS */ + lwpid_t lwpid, + caddr_t xregset) +{ + return PS_OK; +} + +void +ps_plog (const char *fmt, ...) +{ + va_list args; + + va_start (args, fmt); + vfprintf_filtered (gdb_stderr, fmt, args); +} + +/* Look up a symbol in GDB's global symbol table. + Return the symbol's address. + FIXME: it would be more correct to look up the symbol in the context + of the LD_OBJECT_NAME provided. However we're probably fairly safe + as long as there aren't name conflicts with other libraries. */ + +ps_err_e +ps_pglobal_lookup (gdb_ps_prochandle_t ph, + const char *ld_object_name, /* the library name */ + const char *ld_symbol_name, /* the symbol name */ + paddr_t *ld_symbol_addr) /* return the symbol addr */ +{ + struct minimal_symbol *ms; + + ms = lookup_minimal_symbol (ld_symbol_name, NULL, NULL); + + if (!ms) + return PS_NOSYM; + + *ld_symbol_addr = SYMBOL_VALUE_ADDRESS (ms); + + return PS_OK; +} + +/* Worker function for all memory reads and writes: */ +static ps_err_e rw_common (const struct ps_prochandle *ph, + paddr_t addr, + char *buf, + int size, + int write_p); + +/* target_xfer_memory direction consts */ +enum {PS_READ = 0, PS_WRITE = 1}; + +ps_err_e +ps_pdread (gdb_ps_prochandle_t ph, /* read from data segment */ + paddr_t addr, + gdb_ps_read_buf_t buf, + gdb_ps_size_t size) +{ + return rw_common (ph, addr, buf, size, PS_READ); +} + +ps_err_e +ps_pdwrite (gdb_ps_prochandle_t ph, /* write to data segment */ + paddr_t addr, + gdb_ps_write_buf_t buf, + gdb_ps_size_t size) +{ + return rw_common (ph, addr, (char *) buf, size, PS_WRITE); +} + +ps_err_e +ps_ptread (gdb_ps_prochandle_t ph, /* read from text segment */ + paddr_t addr, + gdb_ps_read_buf_t buf, + gdb_ps_size_t size) +{ + return rw_common (ph, addr, buf, size, PS_READ); +} + +ps_err_e +ps_ptwrite (gdb_ps_prochandle_t ph, /* write to text segment */ + paddr_t addr, + gdb_ps_write_buf_t buf, + gdb_ps_size_t size) +{ + return rw_common (ph, addr, (char *) buf, size, PS_WRITE); +} + +static struct cleanup *save_inferior_pid (void); +static void restore_inferior_pid (void *saved_pid); +static char *thr_err_string (td_err_e); +static char *thr_state_string (td_thr_state_e); + +struct ps_prochandle { + int pid; +}; + +struct ps_prochandle main_prochandle; +td_thragent_t * main_threadagent; + +/* + * Common proc_service routine for reading and writing memory. + */ + +/* FIXME: once we've munged the inferior_pid, why can't we + simply call target_read/write_memory and return? */ + + +static ps_err_e +rw_common (const struct ps_prochandle *ph, + paddr_t addr, + char *buf, + int size, + int write_p) +{ + struct cleanup *old_chain = save_inferior_pid (); + int to_do = size; + int done = 0; + + inferior_pid = main_prochandle.pid; + + while (to_do > 0) + { + done = current_target.to_xfer_memory (addr, buf, size, write_p, + ¤t_target); + if (done <= 0) + { + if (write_p == PS_READ) + print_sys_errmsg ("rw_common (): read", errno); + else + print_sys_errmsg ("rw_common (): write", errno); + + return PS_ERR; + } + to_do -= done; + buf += done; + } + do_cleanups (old_chain); + return PS_OK; +} + +/* Cleanup functions used by the register callbacks + (which have to manipulate the global inferior_pid). */ + +ps_err_e +ps_lgetregs (gdb_ps_prochandle_t ph, /* Get LWP general regs */ + lwpid_t lwpid, + prgregset_t gregset) +{ + struct cleanup *old_chain = save_inferior_pid (); + + inferior_pid = BUILD_LWP (lwpid, main_prochandle.pid); + current_target.to_fetch_registers (-1); + + fill_gregset (gregset, -1); + do_cleanups (old_chain); + + return PS_OK; +} + +ps_err_e +ps_lsetregs (gdb_ps_prochandle_t ph, /* Set LWP general regs */ + lwpid_t lwpid, + const prgregset_t gregset) +{ + struct cleanup *old_chain = save_inferior_pid (); + + inferior_pid = BUILD_LWP (lwpid, main_prochandle.pid); + supply_gregset (gregset); + current_target.to_store_registers (-1); + do_cleanups (old_chain); + return PS_OK; +} + +ps_err_e +ps_lgetfpregs (gdb_ps_prochandle_t ph, /* Get LWP float regs */ + lwpid_t lwpid, + prfpregset_t *fpregset) +{ + struct cleanup *old_chain = save_inferior_pid (); + + inferior_pid = BUILD_LWP (lwpid, main_prochandle.pid); + current_target.to_fetch_registers (-1); + fill_fpregset (fpregset, -1); + do_cleanups (old_chain); + return PS_OK; +} + +ps_err_e +ps_lsetfpregs (gdb_ps_prochandle_t ph, /* Set LWP float regs */ + lwpid_t lwpid, + const prfpregset_t *fpregset) +{ + struct cleanup *old_chain = save_inferior_pid (); + + inferior_pid = BUILD_LWP (lwpid, main_prochandle.pid); + supply_fpregset (fpregset); + current_target.to_store_registers (-1); + do_cleanups (old_chain); + return PS_OK; +} + +/* + * ps_getpid + * + * return the main pid for the child process + * (special for Linux -- not used on Solaris) + */ + +pid_t +ps_getpid (gdb_ps_prochandle_t ph) +{ + return ph->pid; +} + +#ifdef TM_I386SOL2_H + +/* Reads the local descriptor table of a LWP. */ + +ps_err_e +ps_lgetLDT (gdb_ps_prochandle_t ph, lwpid_t lwpid, + struct ssd *pldt) +{ + /* NOTE: only used on Solaris, therefore OK to refer to procfs.c */ + extern struct ssd *procfs_find_LDT_entry (int); + struct ssd *ret; + + ret = procfs_find_LDT_entry (BUILD_LWP (lwpid, + PIDGET (main_prochandle.pid))); + if (ret) + { + memcpy (pldt, ret, sizeof (struct ssd)); + return PS_OK; + } + else /* LDT not found. */ + return PS_ERR; +} +#endif /* TM_I386SOL2_H */ + +/* + * Pointers to thread_db functions: + * + * These are a dynamic library mechanism. + * The dlfcn.h interface will be used to initialize these + * so that they point to the appropriate functions in the + * thread_db dynamic library. This is done dynamically + * so that GDB can still run on systems that lack thread_db. + */ + +static td_err_e (*p_td_init) (void); + +static td_err_e (*p_td_ta_new) (const struct ps_prochandle *ph_p, + td_thragent_t **ta_pp); + +static td_err_e (*p_td_ta_delete) (td_thragent_t *ta_p); + +static td_err_e (*p_td_ta_get_nthreads) (const td_thragent_t *ta_p, + int *nthread_p); + + +static td_err_e (*p_td_ta_thr_iter) (const td_thragent_t *ta_p, + td_thr_iter_f *cb, + void *cbdata_p, + td_thr_state_e state, + int ti_pri, + sigset_t *ti_sigmask_p, + unsigned ti_user_flags); + +static td_err_e (*p_td_ta_event_addr) (const td_thragent_t *ta_p, + u_long event, + td_notify_t *notify_p); + +static td_err_e (*p_td_ta_event_getmsg) (const td_thragent_t *ta_p, + td_event_msg_t *msg); + +static td_err_e (*p_td_ta_set_event) (const td_thragent_t *ta_p, + td_thr_events_t *events); + +static td_err_e (*p_td_thr_validate) (const td_thrhandle_t *th_p); + +static td_err_e (*p_td_thr_event_enable) (const td_thrhandle_t *th_p, + int on_off); + +static td_err_e (*p_td_thr_get_info) (const td_thrhandle_t *th_p, + td_thrinfo_t *ti_p); + +static td_err_e (*p_td_thr_getgregs) (const td_thrhandle_t *th_p, + prgregset_t regset); + +static td_err_e (*p_td_thr_setgregs) (const td_thrhandle_t *th_p, + const prgregset_t regset); + +static td_err_e (*p_td_thr_getfpregs) (const td_thrhandle_t *th_p, + prfpregset_t *fpregset); + +static td_err_e (*p_td_thr_setfpregs) (const td_thrhandle_t *th_p, + const prfpregset_t *fpregset); + +static td_err_e (*p_td_ta_map_id2thr) (const td_thragent_t *ta_p, + thread_t tid, + td_thrhandle_t *th_p); + +static td_err_e (*p_td_ta_map_lwp2thr) (const td_thragent_t *ta_p, + lwpid_t lwpid, + td_thrhandle_t *th_p); + +/* + * API and target vector initialization function: thread_db_initialize. + * + * NOTE: this function is deliberately NOT named with the GDB convention + * of module initializer function names that begin with "_initialize". + * This module is NOT intended to be auto-initialized at GDB startup. + * Rather, it will only be initialized when a multi-threaded child + * process is detected. + * + */ + +/* + * Initializer for thread_db library interface. + * This function does the dynamic library stuff (dlopen, dlsym), + * and then calls the thread_db library's one-time initializer + * function (td_init). If everything succeeds, this function + * returns true; otherwise it returns false, and this module + * cannot be used. + */ + +static int +init_thread_db_library () +{ + void *dlhandle; + td_err_e ret; + + /* Open a handle to the "thread_db" dynamic library. */ + if ((dlhandle = dlopen ("libthread_db.so.1", RTLD_NOW)) == NULL) + return 0; /* fail */ + + /* Initialize pointers to the dynamic library functions we will use. + * Note that we are not calling the functions here -- we are only + * establishing pointers to them. + */ + + /* td_init: initialize thread_db library. */ + if ((p_td_init = dlsym (dlhandle, "td_init")) == NULL) + return 0; /* fail */ + /* td_ta_new: register a target process with thread_db. */ + if ((p_td_ta_new = dlsym (dlhandle, "td_ta_new")) == NULL) + return 0; /* fail */ + /* td_ta_delete: un-register a target process with thread_db. */ + if ((p_td_ta_delete = dlsym (dlhandle, "td_ta_delete")) == NULL) + return 0; /* fail */ + + /* td_ta_map_id2thr: get thread handle from thread id. */ + if ((p_td_ta_map_id2thr = dlsym (dlhandle, "td_ta_map_id2thr")) == NULL) + return 0; /* fail */ + /* td_ta_map_lwp2thr: get thread handle from lwp id. */ + if ((p_td_ta_map_lwp2thr = dlsym (dlhandle, "td_ta_map_lwp2thr")) == NULL) + return 0; /* fail */ + /* td_ta_get_nthreads: get number of threads in target process. */ + if ((p_td_ta_get_nthreads = dlsym (dlhandle, "td_ta_get_nthreads")) == NULL) + return 0; /* fail */ + /* td_ta_thr_iter: iterate over all thread handles. */ + if ((p_td_ta_thr_iter = dlsym (dlhandle, "td_ta_thr_iter")) == NULL) + return 0; /* fail */ + + /* td_thr_validate: make sure a thread handle is real and alive. */ + if ((p_td_thr_validate = dlsym (dlhandle, "td_thr_validate")) == NULL) + return 0; /* fail */ + /* td_thr_get_info: get a bunch of info about a thread. */ + if ((p_td_thr_get_info = dlsym (dlhandle, "td_thr_get_info")) == NULL) + return 0; /* fail */ + /* td_thr_getgregs: get general registers for thread. */ + if ((p_td_thr_getgregs = dlsym (dlhandle, "td_thr_getgregs")) == NULL) + return 0; /* fail */ + /* td_thr_setgregs: set general registers for thread. */ + if ((p_td_thr_setgregs = dlsym (dlhandle, "td_thr_setgregs")) == NULL) + return 0; /* fail */ + /* td_thr_getfpregs: get floating point registers for thread. */ + if ((p_td_thr_getfpregs = dlsym (dlhandle, "td_thr_getfpregs")) == NULL) + return 0; /* fail */ + /* td_thr_setfpregs: set floating point registers for thread. */ + if ((p_td_thr_setfpregs = dlsym (dlhandle, "td_thr_setfpregs")) == NULL) + return 0; /* fail */ + + ret = p_td_init (); + if (ret != TD_OK) + { + warning ("init_thread_db: td_init: %s", thr_err_string (ret)); + return 0; + } + + /* Optional functions: + We can still debug even if the following functions are not found. */ + + /* td_ta_event_addr: get the breakpoint address for specified event. */ + p_td_ta_event_addr = dlsym (dlhandle, "td_ta_event_addr"); + + /* td_ta_event_getmsg: get the next event message for the process. */ + p_td_ta_event_getmsg = dlsym (dlhandle, "td_ta_event_getmsg"); + + /* td_ta_set_event: request notification of an event. */ + p_td_ta_set_event = dlsym (dlhandle, "td_ta_set_event"); + + /* td_thr_event_enable: enable event reporting in a thread. */ + p_td_thr_event_enable = dlsym (dlhandle, "td_thr_event_enable"); + + return 1; /* success */ +} + +/* + * Local utility functions: + */ + + +/* + + LOCAL FUNCTION + + save_inferior_pid - Save inferior_pid on the cleanup list + restore_inferior_pid - Restore inferior_pid from the cleanup list + + SYNOPSIS + + struct cleanup *save_inferior_pid (void); + void restore_inferior_pid (void *saved_pid); + + DESCRIPTION + + These two functions act in unison to restore inferior_pid in + case of an error. + + NOTES + + inferior_pid is a global variable that needs to be changed by many + of these routines before calling functions in procfs.c. In order + to guarantee that inferior_pid gets restored (in case of errors), + you need to call save_inferior_pid before changing it. At the end + of the function, you should invoke do_cleanups to restore it. + + */ + +static struct cleanup * +save_inferior_pid (void) +{ +#if TARGET_PTR_BIT > TARGET_INT_BIT + return make_cleanup (restore_inferior_pid, (void *) ((long) inferior_pid)); +#else + return make_cleanup (restore_inferior_pid, (void *) inferior_pid); +#endif +} + +static void +restore_inferior_pid (void *saved_pid) +{ +#if TARGET_PTR_BIT > TARGET_INT_BIT + inferior_pid = (int) ((long) saved_pid); +#else + inferior_pid = (int) saved_pid; +#endif +} + +/* + + LOCAL FUNCTION + + thr_err_string - Convert a thread_db error code to a string + + SYNOPSIS + + char * thr_err_string (errcode) + + DESCRIPTION + + Return a string description of the thread_db errcode. If errcode + is unknown, then return an <unknown> message. + + */ + +static char * +thr_err_string (errcode) + td_err_e errcode; +{ + static char buf[50]; + + switch (errcode) { + case TD_OK: return "generic 'call succeeded'"; + case TD_ERR: return "generic error"; + case TD_NOTHR: return "no thread to satisfy query"; + case TD_NOSV: return "no sync handle to satisfy query"; + case TD_NOLWP: return "no lwp to satisfy query"; + case TD_BADPH: return "invalid process handle"; + case TD_BADTH: return "invalid thread handle"; + case TD_BADSH: return "invalid synchronization handle"; + case TD_BADTA: return "invalid thread agent"; + case TD_BADKEY: return "invalid key"; + case TD_NOMSG: return "no event message for getmsg"; + case TD_NOFPREGS: return "FPU register set not available"; + case TD_NOLIBTHREAD: return "application not linked with libthread"; + case TD_NOEVENT: return "requested event is not supported"; + case TD_NOCAPAB: return "capability not available"; + case TD_DBERR: return "debugger service failed"; + case TD_NOAPLIC: return "operation not applicable to"; + case TD_NOTSD: return "no thread-specific data for this thread"; + case TD_MALLOC: return "malloc failed"; + case TD_PARTIALREG: return "only part of register set was written/read"; + case TD_NOXREGS: return "X register set not available for this thread"; + default: + sprintf (buf, "unknown thread_db error '%d'", errcode); + return buf; + } +} + +/* + + LOCAL FUNCTION + + thr_state_string - Convert a thread_db state code to a string + + SYNOPSIS + + char *thr_state_string (statecode) + + DESCRIPTION + + Return the thread_db state string associated with statecode. + If statecode is unknown, then return an <unknown> message. + + */ + +static char * +thr_state_string (statecode) + td_thr_state_e statecode; +{ + static char buf[50]; + + switch (statecode) { + case TD_THR_STOPPED: return "stopped by debugger"; + case TD_THR_RUN: return "runnable"; + case TD_THR_ACTIVE: return "active"; + case TD_THR_ZOMBIE: return "zombie"; + case TD_THR_SLEEP: return "sleeping"; + case TD_THR_STOPPED_ASLEEP: return "stopped by debugger AND blocked"; + default: + sprintf (buf, "unknown thread_db state %d", statecode); + return buf; + } +} + +/* + * Local thread/event list. + * This data structure will be used to hold a list of threads and + * pending/deliverable events. + */ + +typedef struct THREADINFO { + thread_t tid; /* thread ID */ + pid_t lid; /* process/lwp ID */ + td_thr_state_e state; /* thread state (a la thread_db) */ + td_thr_type_e type; /* thread type (a la thread_db) */ + int pending; /* true if holding a pending event */ + int status; /* wait status of any interesting event */ +} threadinfo; + +threadinfo * threadlist; +int threadlist_max = 0; /* current size of table */ +int threadlist_top = 0; /* number of threads now in table */ +#define THREADLIST_ALLOC 100 /* chunk size by which to expand table */ + +static threadinfo * +insert_thread (tid, lid, state, type) + int tid; + int lid; + td_thr_state_e state; + td_thr_type_e type; +{ + if (threadlist_top >= threadlist_max) + { + threadlist_max += THREADLIST_ALLOC; + threadlist = realloc (threadlist, + threadlist_max * sizeof (threadinfo)); + if (threadlist == NULL) + return NULL; + } + threadlist[threadlist_top].tid = tid; + threadlist[threadlist_top].lid = lid; + threadlist[threadlist_top].state = state; + threadlist[threadlist_top].type = type; + threadlist[threadlist_top].pending = 0; + threadlist[threadlist_top].status = 0; + + return &threadlist[threadlist_top++]; +} + +static void +empty_threadlist () +{ + threadlist_top = 0; +} + +static threadinfo * +next_pending_event () +{ + int i; + + for (i = 0; i < threadlist_top; i++) + if (threadlist[i].pending) + return &threadlist[i]; + + return NULL; +} + +static void +threadlist_iter (func, data, state, type) + int (*func) (); + void *data; + td_thr_state_e state; + td_thr_type_e type; +{ + int i; + + for (i = 0; i < threadlist_top; i++) + if ((state == TD_THR_ANY_STATE || state == threadlist[i].state) && + (type == TD_THR_ANY_TYPE || type == threadlist[i].type)) + if ((*func) (&threadlist[i], data) != 0) + break; + + return; +} + +/* + * Global state + * + * Here we keep state information all collected in one place. + */ + +/* This flag is set when we activate, so that we don't do it twice. + Defined in linux-thread.c and used for inter-target syncronization. */ +extern int using_thread_db; + +/* The process id for which we've stopped. + * This is only set when we actually stop all threads. + * Otherwise it's zero. + */ +static int event_pid; + +/* + * The process id for a new thread to which we've just attached. + * This process needs special handling at resume time. + */ +static int attach_pid; + + +/* + * thread_db event handling: + * + * The mechanism for event notification via the thread_db API. + * These events are implemented as breakpoints. The thread_db + * library gives us an address where we can set a breakpoint. + * When the breakpoint is hit, it represents an event of interest + * such as: + * Thread creation + * Thread death + * Thread reap + */ + +/* Location of the thread creation event breakpoint. The code at this + location in the child process will be called by the pthread library + whenever a new thread is created. By setting a special breakpoint + at this location, GDB can detect when a new thread is created. We + obtain this location via the td_ta_event_addr call. */ + +static CORE_ADDR thread_creation_bkpt_address; + +/* Location of the thread death event breakpoint. The code at this + location in the child process will be called by the pthread library + whenever a thread is destroyed. By setting a special breakpoint at + this location, GDB can detect when a new thread is created. We + obtain this location via the td_ta_event_addr call. */ + +static CORE_ADDR thread_death_bkpt_address; + +/* This function handles the global parts of enabling thread events. + The thread-specific enabling is handled per-thread elsewhere. */ + +static void +enable_thread_event_reporting (ta) + td_thragent_t *ta; +{ + td_thr_events_t events; + td_notify_t notify; + CORE_ADDR addr; + + if (p_td_ta_set_event == NULL || + p_td_ta_event_addr == NULL || + p_td_ta_event_getmsg == NULL || + p_td_thr_event_enable == NULL) + return; /* can't do thread event reporting without these funcs */ + + /* set process wide mask saying which events we are interested in */ + td_event_emptyset (&events); + td_event_addset (&events, TD_CREATE); + td_event_addset (&events, TD_DEATH); + + if (p_td_ta_set_event (ta, &events) != TD_OK) + { + warning ("unable to set global thread event mask"); + return; + } + + /* Delete previous thread event breakpoints, if any. */ + remove_thread_event_breakpoints (); + + /* create breakpoints -- thread creation and death */ + /* thread creation */ + /* get breakpoint location */ + if (p_td_ta_event_addr (ta, TD_CREATE, ¬ify) != TD_OK) + { + warning ("unable to get location for thread creation breakpoint"); + return; + } + + /* Set up the breakpoint. */ + create_thread_event_breakpoint (notify.u.bptaddr); + + /* Save it's location. */ + thread_creation_bkpt_address = notify.u.bptaddr; + + /* thread death */ + /* get breakpoint location */ + if (p_td_ta_event_addr (ta, TD_DEATH, ¬ify) != TD_OK) + { + warning ("unable to get location for thread death breakpoint"); + return; + } + /* Set up the breakpoint. */ + create_thread_event_breakpoint (notify.u.bptaddr); + + /* Save it's location. */ + thread_death_bkpt_address = notify.u.bptaddr; +} + +/* This function handles the global parts of disabling thread events. + The thread-specific enabling is handled per-thread elsewhere. */ + +static void +disable_thread_event_reporting (ta) + td_thragent_t *ta; +{ + td_thr_events_t events; + + /* set process wide mask saying we aren't interested in any events */ + td_event_emptyset (&events); + p_td_ta_set_event (main_threadagent, &events); + + /* Delete thread event breakpoints, if any. */ + remove_thread_event_breakpoints (); + thread_creation_bkpt_address = 0; + thread_death_bkpt_address = 0; +} + +/* check_for_thread_event + + if it's a thread event we recognize (currently + we only recognize creation and destruction + events), return 1; else return 0. */ + + +static int +check_for_thread_event (struct target_waitstatus *tws, int event_pid) +{ + /* FIXME: to be more efficient, we should keep a static + list of threads, and update it only here (with td_ta_thr_iter). */ +} + +static void +thread_db_push_target (void) +{ + /* Called ONLY from thread_db_new_objfile after td_ta_new call succeeds. */ + + /* Push this target vector */ + push_target (&thread_db_ops); + /* Find the underlying process-layer target for calling later. */ + target_beneath = find_target_beneath (&thread_db_ops); + using_thread_db = 1; + /* Turn on thread_db event-reporting API. */ + enable_thread_event_reporting (main_threadagent); +} + +static void +thread_db_unpush_target (void) +{ + /* Must be called whenever we remove ourself from the target stack! */ + + using_thread_db = 0; + target_beneath = NULL; + + /* delete local list of threads */ + empty_threadlist (); + /* Turn off the thread_db API. */ + p_td_ta_delete (main_threadagent); + /* Unpush this target vector */ + unpush_target (&thread_db_ops); + /* Reset linuxthreads module. */ + linuxthreads_discard_global_state (); +} + +/* + * New objfile hook function: + * Called for each new objfile (image, shared lib) in the target process. + * + * The purpose of this function is to detect that the target process + * is linked with the (appropriate) thread library. So every time a + * new target shared library is detected, we will call td_ta_new. + * If it succeeds, we know we have a multi-threaded target process + * that we can debug using the thread_db API. + */ + +/* + * new_objfile function: + * + * connected to target_new_objfile_hook, this function gets called + * every time a new binary image is loaded. + * + * At each call, we attempt to open the thread_db connection to the + * child process. If it succeeds, we know we have a libthread process + * and we can debug it with this target vector. Therefore we push + * ourself onto the target stack. + */ + +static void (*target_new_objfile_chain) (struct objfile *objfile); +static int stop_or_attach_thread_callback (const td_thrhandle_t *th, + void *data); +static int wait_thread_callback (const td_thrhandle_t *th, + void *data); + +static void +thread_db_new_objfile (struct objfile *objfile) +{ + td_err_e ret; + + if (using_thread_db) /* libthread already detected, and */ + goto quit; /* thread target vector activated. */ + + if (objfile == NULL) + goto quit; /* un-interesting object file */ + + /* Initialize our "main prochandle" with the main inferior pid. */ + main_prochandle.pid = PIDGET (inferior_pid); + + /* Now attempt to open a thread_db connection to the + thread library running in the child process. */ + ret = p_td_ta_new (&main_prochandle, &main_threadagent); + switch (ret) { + default: + warning ("Unexpected error initializing thread_db: %s", + thr_err_string (ret)); + break; + case TD_NOLIBTHREAD: /* expected: no libthread in child process (yet) */ + break; + case TD_OK: /* libthread detected in child: we go live now! */ + thread_db_push_target (); + event_pid = inferior_pid; /* for resume */ + + /* Now stop everyone else, and attach any new threads you find. */ + p_td_ta_thr_iter (main_threadagent, + stop_or_attach_thread_callback, + (void *) 0, + TD_THR_ANY_STATE, + TD_THR_LOWEST_PRIORITY, + TD_SIGNO_MASK, + TD_THR_ANY_USER_FLAGS); + + /* Now go call wait on all the threads you've stopped: + This allows us to absorb the SIGKILL event, and to make sure + that the thread knows that it is stopped (Linux peculiarity). */ + p_td_ta_thr_iter (main_threadagent, + wait_thread_callback, + (void *) 0, + TD_THR_ANY_STATE, + TD_THR_LOWEST_PRIORITY, + TD_SIGNO_MASK, + TD_THR_ANY_USER_FLAGS); + + break; + } +quit: + if (target_new_objfile_chain) + target_new_objfile_chain (objfile); +} + + +/* + + LOCAL FUNCTION + + thread_db_alive - test thread for "aliveness" + + SYNOPSIS + + static bool thread_db_alive (int pid); + + DESCRIPTION + + returns true if thread still active in inferior. + + */ + +static int +thread_db_alive (pid) + int pid; +{ + if (is_thread (pid)) /* user-space (non-kernel) thread */ + { + td_thrhandle_t th; + td_err_e ret; + + pid = GET_THREAD (pid); + if ((ret = p_td_ta_map_id2thr (main_threadagent, pid, &th)) != TD_OK) + return 0; /* thread not found */ + if ((ret = p_td_thr_validate (&th)) != TD_OK) + return 0; /* thread not valid */ + return 1; /* known thread: return true */ + } + else if (target_beneath->to_thread_alive) + return target_beneath->to_thread_alive (pid); + else + return 0; /* default to "not alive" (shouldn't happen anyway) */ +} + +/* + * get_lwp_from_thread_handle + */ + +static int /* lwpid_t or pid_t */ +get_lwp_from_thread_handle (th) + td_thrhandle_t *th; +{ + td_thrinfo_t ti; + td_err_e ret; + + if ((ret = p_td_thr_get_info (th, &ti)) != TD_OK) + error ("get_lwp_from_thread_handle: thr_get_info failed: %s", + thr_err_string (ret)); + + return ti.ti_lid; +} + +/* + * get_lwp_from_thread_id + */ + +static int /* lwpid_t or pid_t */ +get_lwp_from_thread_id (tid) + int tid; /* thread_t? */ +{ + td_thrhandle_t th; + td_err_e ret; + + if ((ret = p_td_ta_map_id2thr (main_threadagent, tid, &th)) != TD_OK) + error ("get_lwp_from_thread_id: map_id2thr failed: %s", + thr_err_string (ret)); + + return get_lwp_from_thread_handle (&th); +} + +/* + * pid_to_str has to handle user-space threads. + * If not a user-space thread, then pass the request on to the + * underlying stratum if it can handle it: else call normal_pid_to_str. + */ + +static char * +thread_db_pid_to_str (int pid) +{ + static char buf[100]; + td_thrhandle_t th; + td_thrinfo_t ti; + td_err_e ret; + + if (is_thread (pid)) + { + if ((ret = p_td_ta_map_id2thr (main_threadagent, + GET_THREAD (pid), + &th)) != TD_OK) + error ("thread_db: map_id2thr failed: %s", thr_err_string (ret)); + + if ((ret = p_td_thr_get_info (&th, &ti)) != TD_OK) + error ("thread_db: thr_get_info failed: %s", thr_err_string (ret)); + + if (ti.ti_state == TD_THR_ACTIVE && + ti.ti_lid != 0) + sprintf (buf, "Thread %d (LWP %d)", ti.ti_tid, ti.ti_lid); + else + sprintf (buf, "Thread %d (%s)", ti.ti_tid, + thr_state_string (ti.ti_state)); + } + else if (GET_LWP (pid)) + sprintf (buf, "LWP %d", GET_LWP (pid)); + else return normal_pid_to_str (pid); + + return buf; +} + +/* + * thread_db target vector functions: + */ + +static void +thread_db_files_info (struct target_ops *tgt_vector) +{ + /* This function will be unnecessary in real life. */ + printf_filtered ("thread_db stratum:\n"); + target_beneath->to_files_info (tgt_vector); +} + +/* + * xfer_memory has to munge the inferior_pid before passing the call + * down to the target layer. + */ + +static int +thread_db_xfer_memory (memaddr, myaddr, len, dowrite, target) + CORE_ADDR memaddr; + char *myaddr; + int len; + int dowrite; + struct target_ops *target; /* ignored */ +{ + struct cleanup *old_chain; + int ret; + + old_chain = save_inferior_pid (); + + if (is_thread (inferior_pid) || + !target_thread_alive (inferior_pid)) + { + /* FIXME: use the LID/LWP, so that underlying process layer + can read memory from specific threads? */ + inferior_pid = main_prochandle.pid; + } + + ret = target_beneath->to_xfer_memory (memaddr, myaddr, len, + dowrite, target); + do_cleanups (old_chain); + return ret; +} + +/* + * fetch_registers has to determine if inferior_pid is a user-space thread. + * If so, we use the thread_db API to get the registers. + * And if not, we call the underlying process stratum. + */ + +static void +thread_db_fetch_registers (regno) + int regno; +{ + td_thrhandle_t thandle; + prfpregset_t fpregset; + prgregset_t gregset; + thread_t thread; + td_err_e ret; + + if (!is_thread (inferior_pid)) /* kernel thread */ + { /* pass the request on to the target underneath. */ + target_beneath->to_fetch_registers (regno); + return; + } + + /* convert inferior_pid into a td_thrhandle_t */ + + if ((thread = GET_THREAD (inferior_pid)) == 0) + error ("fetch_registers: thread == 0"); + + if ((ret = p_td_ta_map_id2thr (main_threadagent, thread, &thandle)) != TD_OK) + error ("fetch_registers: td_ta_map_id2thr: %s", thr_err_string (ret)); + + /* Get the integer regs: + For the sparc, TD_PARTIALREG means that only i0->i7, l0->l7, + pc and sp are saved (by a thread context switch). */ + if ((ret = p_td_thr_getgregs (&thandle, gregset)) != TD_OK && + ret != TD_PARTIALREG) + error ("fetch_registers: td_thr_getgregs %s", thr_err_string (ret)); + + /* And, now the fp regs */ + if ((ret = p_td_thr_getfpregs (&thandle, &fpregset)) != TD_OK && + ret != TD_NOFPREGS) + error ("fetch_registers: td_thr_getfpregs %s", thr_err_string (ret)); + +/* Note that we must call supply_{g fp}regset *after* calling the td routines + because the td routines call ps_lget* which affect the values stored in the + registers array. */ + + supply_gregset (gregset); + supply_fpregset (&fpregset); + +} + +/* + * store_registers has to determine if inferior_pid is a user-space thread. + * If so, we use the thread_db API to get the registers. + * And if not, we call the underlying process stratum. + */ + +static void +thread_db_store_registers (regno) + int regno; +{ + td_thrhandle_t thandle; + prfpregset_t fpregset; + prgregset_t gregset; + thread_t thread; + td_err_e ret; + + if (!is_thread (inferior_pid)) /* Kernel thread: */ + { /* pass the request on to the underlying target vector. */ + target_beneath->to_store_registers (regno); + return; + } + + /* convert inferior_pid into a td_thrhandle_t */ + + if ((thread = GET_THREAD (inferior_pid)) == 0) + error ("store_registers: thread == 0"); + + if ((ret = p_td_ta_map_id2thr (main_threadagent, thread, &thandle)) != TD_OK) + error ("store_registers: td_ta_map_id2thr %s", thr_err_string (ret)); + + if (regno != -1) + { /* Not writing all the regs */ + /* save new register value */ + /* MVS: I don't understand this... */ + char old_value[REGISTER_SIZE]; + + memcpy (old_value, ®isters[REGISTER_BYTE (regno)], REGISTER_SIZE); + + if ((ret = p_td_thr_getgregs (&thandle, gregset)) != TD_OK) + error ("store_registers: td_thr_getgregs %s", thr_err_string (ret)); + if ((ret = p_td_thr_getfpregs (&thandle, &fpregset)) != TD_OK) + error ("store_registers: td_thr_getfpregs %s", thr_err_string (ret)); + + /* restore new register value */ + memcpy (®isters[REGISTER_BYTE (regno)], old_value, REGISTER_SIZE); + + } + + fill_gregset (gregset, regno); + fill_fpregset (&fpregset, regno); + + if ((ret = p_td_thr_setgregs (&thandle, gregset)) != TD_OK) + error ("store_registers: td_thr_setgregs %s", thr_err_string (ret)); + if ((ret = p_td_thr_setfpregs (&thandle, &fpregset)) != TD_OK && + ret != TD_NOFPREGS) + error ("store_registers: td_thr_setfpregs %s", thr_err_string (ret)); +} + +static void +handle_new_thread (tid, lid, verbose) + int tid; /* user thread id */ + int lid; /* kernel thread id */ + int verbose; +{ + int gdb_pid = BUILD_THREAD (tid, main_prochandle.pid); + int wait_pid, wait_status; + + if (verbose) + printf_filtered ("[New %s]\n", target_pid_to_str (gdb_pid)); + add_thread (gdb_pid); + + if (lid != main_prochandle.pid) + { + attach_thread (lid); + /* According to the Eric Paire model, we now have to send + the restart signal to the new thread -- however, empirically, + I do not find that to be necessary. */ + attach_pid = lid; + } +} + +static void +test_for_new_thread (tid, lid, verbose) + int tid; + int lid; + int verbose; +{ + if (!in_thread_list (BUILD_THREAD (tid, main_prochandle.pid))) + handle_new_thread (tid, lid, verbose); +} + +/* + * Callback function that gets called once per USER thread + * (i.e., not kernel) thread by td_ta_thr_iter. + */ + +static int +find_new_threads_callback (th, ignored) + const td_thrhandle_t *th; + void *ignored; +{ + td_thrinfo_t ti; + td_err_e ret; + + if ((ret = p_td_thr_get_info (th, &ti)) != TD_OK) + { + warning ("find_new_threads_callback: %s", thr_err_string (ret)); + return -1; /* bail out, get_info failed. */ + } + + /* FIXME: + As things now stand, this should never detect a new thread. + But if it does, we could be in trouble because we aren't calling + wait_thread_callback for it. */ + test_for_new_thread (ti.ti_tid, ti.ti_lid, 0); + return 0; +} + +/* + * find_new_threads uses the thread_db iterator function to discover + * user-space threads. Then if the underlying process stratum has a + * find_new_threads method, we call that too. + */ + +static void +thread_db_find_new_threads () +{ + if (inferior_pid == -1) /* FIXME: still necessary? */ + { + printf_filtered ("No process.\n"); + return; + } + p_td_ta_thr_iter (main_threadagent, + find_new_threads_callback, + (void *) 0, + TD_THR_ANY_STATE, + TD_THR_LOWEST_PRIORITY, + TD_SIGNO_MASK, + TD_THR_ANY_USER_FLAGS); + if (target_beneath->to_find_new_threads) + target_beneath->to_find_new_threads (); +} + +/* + * Resume all threads, or resume a single thread. + * If step is true, then single-step the appropriate thread + * (or single-step inferior_pid, but continue everyone else). + * If signo is true, then send that signal to at least one thread. + */ + +/* + * This function is called once for each thread before resuming. + * It sends continue (no step, and no signal) to each thread except + * the main thread, and + * the event thread (the one that stopped at a breakpoint etc.) + * + * The event thread is handled separately so that it can be sent + * the stepping and signal args with which target_resume was called. + * + * The main thread is resumed last, so that the thread_db proc_service + * callbacks will still work during the iterator function. + */ + +static int +resume_thread_callback (th, data) + const td_thrhandle_t *th; + void *data; +{ + td_thrinfo_t ti; + td_err_e ret; + + if ((ret = p_td_thr_get_info (th, &ti)) != TD_OK) + { + warning ("resume_thread_callback: %s", thr_err_string (ret)); + return -1; /* bail out, get_info failed. */ + } + /* FIXME: + As things now stand, this should never detect a new thread. + But if it does, we could be in trouble because we aren't calling + wait_thread_callback for it. */ + test_for_new_thread (ti.ti_tid, ti.ti_lid, 1); + + if (ti.ti_lid != main_prochandle.pid && + ti.ti_lid != event_pid) + { + /* Unconditionally continue the thread with no signal. + Only the event thread will get a signal of any kind. */ + + target_beneath->to_resume (ti.ti_lid, 0, 0); + } + return 0; +} + +static int +new_resume_thread_callback (thread, data) + threadinfo *thread; + void *data; +{ + if (thread->lid != event_pid && + thread->lid != main_prochandle.pid) + { + /* Unconditionally continue the thread with no signal (for now). */ + + target_beneath->to_resume (thread->lid, 0, 0); + } + return 0; +} + +static int last_resume_pid; +static int last_resume_step; +static int last_resume_signo; + +static void +thread_db_resume (pid, step, signo) + int pid; + int step; + enum target_signal signo; +{ + last_resume_pid = pid; + last_resume_step = step; + last_resume_signo = signo; + + /* resuming a specific pid? */ + if (pid != -1) + { + if (is_thread (pid)) + pid = get_lwp_from_thread_id (GET_THREAD (pid)); + else if (GET_LWP (pid)) + pid = GET_LWP (pid); + } + + /* Apparently the interpretation of 'pid' is dependent on 'step': + If step is true, then a specific pid means 'step only this pid'. + But if step is not true, then pid means 'continue ALL pids, but + give the signal only to this one'. */ + if (pid != -1 && step) + { + /* FIXME: is this gonna work in all circumstances? */ + target_beneath->to_resume (pid, step, signo); + } + else + { + /* 1) Continue all threads except the event thread and the main thread. + 2) resume the event thread with step and signo. + 3) If event thread != main thread, continue the main thread. + + Note: order of 2 and 3 may need to be reversed. */ + + threadlist_iter (new_resume_thread_callback, + (void *) 0, + TD_THR_ANY_STATE, + TD_THR_ANY_TYPE); + /* now resume event thread, and if necessary also main thread. */ + if (event_pid) + { + target_beneath->to_resume (event_pid, step, signo); + } + if (event_pid != main_prochandle.pid) + { + target_beneath->to_resume (main_prochandle.pid, 0, 0); + } + } +} + +/* All new threads will be attached. + All previously known threads will be stopped using kill (SIGKILL). */ + +static int +stop_or_attach_thread_callback (const td_thrhandle_t *th, void *data) +{ + td_thrinfo_t ti; + td_err_e ret; + int gdb_pid; + int on_off = 1; + + if ((ret = p_td_thr_get_info (th, &ti)) != TD_OK) + { + warning ("stop_or_attach_thread_callback: %s", thr_err_string (ret)); + return -1; /* bail out, get_info failed. */ + } + + /* First add it to our internal list. + We build this list anew at every wait event. */ + insert_thread (ti.ti_tid, ti.ti_lid, ti.ti_state, ti.ti_type); + /* Now: if we've already seen it, stop it, else add it and attach it. */ + gdb_pid = BUILD_THREAD (ti.ti_tid, main_prochandle.pid); + if (!in_thread_list (gdb_pid)) /* new thread */ + { + handle_new_thread (ti.ti_tid, ti.ti_lid, 1); + /* Enable thread events */ + if (p_td_thr_event_enable) + if ((ret = p_td_thr_event_enable (th, on_off)) != TD_OK) + warning ("stop_or_attach_thread: %s", thr_err_string (ret)); + } + else if (ti.ti_lid != event_pid && + ti.ti_lid != main_prochandle.pid) + { + ret = (td_err_e) kill (ti.ti_lid, SIGSTOP); + } + + return 0; +} + +/* + * Wait for signal N from pid PID. + * If wait returns any other signals, put them back before returning. + */ + +static void +wait_for_stop (pid) + int pid; +{ + int i; + int retpid; + int status; + + /* Array of wait/signal status */ + /* FIXME: wrong data structure, we need a queue. + Realtime signals may be delivered more than once. + And at that, we really can't handle them (see below). */ +#if defined (NSIG) + static int wstatus [NSIG]; +#elif defined (_NSIG) + static int wstatus [_NSIG]; +#else +#error No definition for number of signals! +#endif + + /* clear wait/status list */ + memset (&wstatus, 0, sizeof (wstatus)); + + /* Now look for SIGSTOP event on all threads except event thread. */ + do { + errno = 0; + if (pid == main_prochandle.pid) + retpid = waitpid (pid, &status, 0); + else + retpid = waitpid (pid, &status, __WCLONE); + + if (retpid > 0) + if (WSTOPSIG (status) == SIGSTOP) + { + /* Got the SIGSTOP event we're looking for. + Throw it away, and throw any other events back! */ + for (i = 0; i < sizeof(wstatus) / sizeof (wstatus[0]); i++) + if (wstatus[i]) + if (i != SIGSTOP) + { + kill (retpid, i); + } + break; /* all done */ + } + else + { + int signo; + /* Oops, got an event other than SIGSTOP. + Save it, and throw it back after we find the SIGSTOP event. */ + + /* FIXME (how?) This method is going to fail for realtime + signals, which cannot be put back simply by using kill. */ + + if (WIFEXITED (status)) + error ("Ack! Thread Exited event. What do I do now???"); + else if (WIFSTOPPED (status)) + signo = WSTOPSIG (status); + else + signo = WTERMSIG (status); + + /* If a thread other than the event thread has hit a GDB + breakpoint (as opposed to some random trap signal), then + just arrange for it to hit it again later. Back up the + PC if necessary. Don't forward the SIGTRAP signal to + the thread. We will handle the current event, eventually + we will resume all the threads, and this one will get + it's breakpoint trap again. + + If we do not do this, then we run the risk that the user + will delete or disable the breakpoint, but the thread will + have already tripped on it. */ + + if (retpid != event_pid && + signo == SIGTRAP && + breakpoint_inserted_here_p (read_pc_pid (retpid) - + DECR_PC_AFTER_BREAK)) + { + /* Set the pc to before the trap and DO NOT re-send the signal */ + if (DECR_PC_AFTER_BREAK) + write_pc_pid (read_pc_pid (retpid) - DECR_PC_AFTER_BREAK, + retpid); + } + + /* Since SIGINT gets forwarded to the entire process group + (in the case where ^C is typed at the tty / console), + just ignore all SIGINTs from other than the event thread. */ + else if (retpid != event_pid && signo == SIGINT) + { /* do nothing. Signal will disappear into oblivion! */ + ; + } + + else /* This is some random signal other than a breakpoint. */ + { + wstatus [signo] = 1; + } + child_resume (retpid, 0, TARGET_SIGNAL_0); + continue; + } + + } while (errno == 0 || errno == EINTR); +} + +/* + * wait_thread_callback + * + * Calls waitpid for each thread, repeatedly if necessary, until + * SIGSTOP is returned. Afterward, if any other signals were returned + * by waitpid, return them to the thread's pending queue by calling kill. + */ + +static int +wait_thread_callback (const td_thrhandle_t *th, void *data) +{ + td_thrinfo_t ti; + td_err_e ret; + + if ((ret = p_td_thr_get_info (th, &ti)) != TD_OK) + { + warning ("wait_thread_callback: %s", thr_err_string (ret)); + return -1; /* bail out, get_info failed. */ + } + + /* This callback to act on all threads except the event thread: */ + if (ti.ti_lid == event_pid || /* no need to wait (no sigstop) */ + ti.ti_lid == main_prochandle.pid) /* no need to wait (already waited) */ + return 0; /* don't wait on the event thread. */ + + wait_for_stop (ti.ti_lid); + return 0; /* finished: next thread. */ +} + +static int +new_wait_thread_callback (thread, data) + threadinfo *thread; + void *data; +{ + /* don't wait on the event thread -- it's already stopped and waited. + Ditto the main thread. */ + if (thread->lid != event_pid && + thread->lid != main_prochandle.pid) + { + wait_for_stop (thread->lid); + } + return 0; +} + +/* + * Wait for any thread to stop, by calling the underlying wait method. + * The PID returned by the underlying target may be a kernel thread, + * in which case we will want to convert it to the corresponding + * user-space thread. + */ + +static int +thread_db_wait (int pid, struct target_waitstatus *ourstatus) +{ + td_thrhandle_t thandle; + td_thrinfo_t ti; + td_err_e ret; + lwpid_t lwp; + int retpid; + int status; + int save_errno; + + /* OK, we're about to wait for an event from the running inferior. + Make sure we're ignoring the right signals. */ + + check_all_signal_numbers (); /* see if magic signals changed. */ + + event_pid = 0; + attach_pid = 0; + + /* FIXME: should I do the wait right here inline? */ +#if 0 + if (pid == -1) + lwp = -1; + else + lwp = get_lwp_from_thread_id (GET_THREAD (pid)); +#endif + + + save_errno = linux_child_wait (-1, &retpid, &status); + store_waitstatus (ourstatus, status); + + /* Thread ID is irrelevant if the target process exited. + FIXME: do I have any killing to do? + Can I get this event mistakenly from a thread? */ + if (ourstatus->kind == TARGET_WAITKIND_EXITED) + return retpid; + + /* OK, we got an event of interest. + Go stop all threads and look for new ones. + FIXME: maybe don't do this for the restart signal? Optimization... */ + event_pid = retpid; + + /* If the last call to resume was for a specific thread, then we don't + need to stop everyone else: they should already be stopped. */ + if (last_resume_step == 0 || last_resume_pid == -1) + { + /* Main thread must be stopped before calling the iterator. */ + if (retpid != main_prochandle.pid) + { + kill (main_prochandle.pid, SIGSTOP); + wait_for_stop (main_prochandle.pid); + } + + empty_threadlist (); + /* Now stop everyone else, and attach any new threads you find. */ + p_td_ta_thr_iter (main_threadagent, + stop_or_attach_thread_callback, + (void *) 0, + TD_THR_ANY_STATE, + TD_THR_LOWEST_PRIORITY, + TD_SIGNO_MASK, + TD_THR_ANY_USER_FLAGS); + + /* Now go call wait on all the threads we've stopped: + This allows us to absorb the SIGKILL event, and to make sure + that the thread knows that it is stopped (Linux peculiarity). */ + + threadlist_iter (new_wait_thread_callback, + (void *) 0, + TD_THR_ANY_STATE, + TD_THR_ANY_TYPE); + } + + /* Convert the kernel thread id to the corresponding thread id. */ + + /* If the process layer does not furnish an lwp, + then perhaps the returned pid IS the lwp... */ + if ((lwp = GET_LWP (retpid)) == 0) + lwp = retpid; + + if ((ret = p_td_ta_map_lwp2thr (main_threadagent, lwp, &thandle)) != TD_OK) + return retpid; /* LWP is not mapped onto a user-space thread. */ + + if ((ret = p_td_thr_validate (&thandle)) != TD_OK) + return retpid; /* LWP is not mapped onto a valid thread. */ + + if ((ret = p_td_thr_get_info (&thandle, &ti)) != TD_OK) + { + warning ("thread_db: thr_get_info failed ('%s')", thr_err_string (ret)); + return retpid; + } + + retpid = BUILD_THREAD (ti.ti_tid, main_prochandle.pid); + /* If this is a new user thread, notify GDB about it. */ + if (!in_thread_list (retpid)) + { + printf_filtered ("[New %s]\n", target_pid_to_str (retpid)); + add_thread (retpid); + } + +#if 0 + /* Now detect if this is a thread creation/deletion event: */ + check_for_thread_event (ourstatus, retpid); +#endif + return retpid; +} + +/* + * kill has to call the underlying kill. + * FIXME: I'm not sure if it's necessary to check inferior_pid any more, + * but we might need to fix inferior_pid up if it's a user thread. + */ + +static int +kill_thread_callback (th, data) + td_thrhandle_t *th; + void *data; +{ + td_thrinfo_t ti; + td_err_e ret; + + /* Fixme: + For Linux, threads may need to be waited. */ + if ((ret = p_td_thr_get_info (th, &ti)) != TD_OK) + { + warning ("kill_thread_callback: %s", thr_err_string (ret)); + return -1; /* bail out, get_info failed. */ + } + + if (ti.ti_lid != main_prochandle.pid) + { + kill (ti.ti_lid, SIGKILL); + } + return 0; +} + + +static void thread_db_kill (void) +{ + int rpid; + int status; + + /* Fixme: + For Linux, threads may need to be waited. */ + if (inferior_pid != 0) + { + /* Go kill the children first. Save the main thread for last. */ + p_td_ta_thr_iter (main_threadagent, + kill_thread_callback, + (void *) 0, + TD_THR_ANY_STATE, + TD_THR_LOWEST_PRIORITY, + TD_SIGNO_MASK, + TD_THR_ANY_USER_FLAGS); + + /* Turn off thread_db event-reporting API *before* killing the + main thread, since this operation requires child memory access. + Can't move this into thread_db_unpush target because then + detach would not work. */ + disable_thread_event_reporting (main_threadagent); + + inferior_pid = main_prochandle.pid; + + /* + * Since both procfs_kill and ptrace_kill call target_mourn, + * it should be sufficient for me to call one of them. + * That will result in my mourn being called, which will both + * unpush me and call the underlying mourn. + */ + target_beneath->to_kill (); + } + + /* Wait for all threads. */ + /* FIXME: need a universal wait_for_signal func? */ + do + { + rpid = waitpid (-1, &status, __WCLONE | WNOHANG); + } + while (rpid > 0 || errno == EINTR); + + do + { + rpid = waitpid (-1, &status, WNOHANG); + } + while (rpid > 0 || errno == EINTR); +} + +/* + * Mourn has to remove us from the target stack, + * and then call the underlying mourn. + */ + +static void thread_db_mourn_inferior (void) +{ + thread_db_unpush_target (); + target_mourn_inferior (); /* call the underlying mourn */ +} + +/* + * Detach has to remove us from the target stack, + * and then call the underlying detach. + * + * But first, it has to detach all the cloned threads! + */ + +static int +detach_thread_callback (th, data) + td_thrhandle_t *th; + void *data; +{ + /* Called once per thread. */ + td_thrinfo_t ti; + td_err_e ret; + + if ((ret = p_td_thr_get_info (th, &ti)) != TD_OK) + { + warning ("detach_thread_callback: %s", thr_err_string (ret)); + return -1; /* bail out, get_info failed. */ + } + + if (!in_thread_list (BUILD_THREAD (ti.ti_tid, main_prochandle.pid))) + return 0; /* apparently we don't know this one. */ + + /* Save main thread for last, or the iterator will fail! */ + if (ti.ti_lid != main_prochandle.pid) + { + struct cleanup *old_chain; + int off = 0; + + /* Time to detach this thread. + First disable thread_db event reporting for the thread. */ + if (p_td_thr_event_enable && + (ret = p_td_thr_event_enable (th, off)) != TD_OK) + { + warning ("detach_thread_callback: %s\n", thr_err_string (ret)); + return 0; + } + + /* Now cancel any pending SIGTRAPS. FIXME! */ + + /* Call underlying detach method. FIXME just detach it. */ + old_chain = save_inferior_pid (); + inferior_pid = ti.ti_lid; + detach (TARGET_SIGNAL_0); + do_cleanups (old_chain); + } + return 0; +} + +static void +thread_db_detach (char *args, int from_tty) +{ + td_err_e ret; + + if ((ret = p_td_ta_thr_iter (main_threadagent, + detach_thread_callback, + (void *) 0, + TD_THR_ANY_STATE, + TD_THR_LOWEST_PRIORITY, + TD_SIGNO_MASK, + TD_THR_ANY_USER_FLAGS)) + != TD_OK) + warning ("detach (thr_iter): %s", thr_err_string (ret)); + + /* Turn off thread_db event-reporting API + (before detaching the main thread) */ + disable_thread_event_reporting (main_threadagent); + + thread_db_unpush_target (); + + /* above call nullifies target_beneath, so don't use that! */ + inferior_pid = PIDGET (inferior_pid); + target_detach (args, from_tty); +} + + +/* + * We never want to actually create the inferior! + * + * If this is ever called, it means we were on the target stack + * when the user said "run". But we don't want to be on the new + * inferior's target stack until the thread_db / libthread + * connection is ready to be made. + * + * So, what shall we do? + * Unpush ourselves from the stack, and then invoke + * find_default_create_inferior, which will invoke the + * appropriate process_stratum target to do the create. + */ + +static void +thread_db_create_inferior (exec_file, allargs, env) + char *exec_file; + char *allargs; + char **env; +{ + thread_db_unpush_target (); + find_default_create_inferior (exec_file, allargs, env); +} + +/* + * Thread_db target vector initializer. + */ + +void +init_thread_db_ops () +{ + thread_db_ops.to_shortname = "multi-thread"; + thread_db_ops.to_longname = "multi-threaded child process."; + thread_db_ops.to_doc = "Threads and pthreads support."; + thread_db_ops.to_files_info = thread_db_files_info; + thread_db_ops.to_create_inferior = thread_db_create_inferior; + thread_db_ops.to_detach = thread_db_detach; + thread_db_ops.to_wait = thread_db_wait; + thread_db_ops.to_resume = thread_db_resume; + thread_db_ops.to_mourn_inferior = thread_db_mourn_inferior; + thread_db_ops.to_kill = thread_db_kill; + thread_db_ops.to_xfer_memory = thread_db_xfer_memory; + thread_db_ops.to_fetch_registers = thread_db_fetch_registers; + thread_db_ops.to_store_registers = thread_db_store_registers; + thread_db_ops.to_thread_alive = thread_db_alive; + thread_db_ops.to_find_new_threads = thread_db_find_new_threads; + thread_db_ops.to_pid_to_str = thread_db_pid_to_str; + thread_db_ops.to_stratum = thread_stratum; + thread_db_ops.to_has_thread_control = tc_schedlock; + thread_db_ops.to_magic = OPS_MAGIC; +} +#endif /* HAVE_STDINT_H */ + +/* + * Module constructor / initializer function. + * If connection to thread_db dynamic library is successful, + * then initialize this module's target vectors and the + * new_objfile hook. + */ + + +void +_initialize_thread_db () +{ +#ifdef HAVE_STDINT_H /* stub out entire module, leave initializer empty */ + if (init_thread_db_library ()) + { + init_thread_db_ops (); + add_target (&thread_db_ops); + /* + * Hook up to the new_objfile event. + * If someone is already there, arrange for him to be called + * after we are. + */ + target_new_objfile_chain = target_new_objfile_hook; + target_new_objfile_hook = thread_db_new_objfile; + } +#endif /* HAVE_STDINT_H */ +} + |